Photoflash lamp



Jan. 18, 1955 P. HAAS v PHOTOFLASH LAMP Filed Feb. 3, 1951 INVENTOR PA UL HAAS BY A; MX

United States Patent PHOTOFLASH LAMP Paul Haas, New Hyde Park, N. Y.,assignor to Sylvania Electric Products Inc., a corporation ofMassachusetts Application February 3, 1951, Serial No. 209,264 2 Claims.(Cl. 67-31) This invention relates to particularly, it relates to aphotoflash lamp.

Since photoflash lamps of the type which are presently used arenecessarily discarded after the initial flash it is but natural thatmany attempts have been made to eliminate as many of its component partsas is possible while still retaining all its functional components andwithout reducing the quality of the lamp. In following along this theorythe screw type bases have been re placed in some part with lamps of thebayonet type there by reducing the amount of brass in the base portionas well as in the socket itself.

It is an object of this invention to further reduce the essentialcomponents which go into the making of these photoflash lamps.

It is a further object of this invention to devise a baseless type lampin which no brass is used.

It has been found that these objects and other advantages can beattained by forming a solid kuobular glass member at the bottom of theflashlamp during the sealing operation with the metal leads projectingtherethrough and arranged on said knob in a manner which permits oftheir use in making electrical contact with a source of power through asocket adapted for this purpose.

In the drawings illustrating an embodiment of this invention Figure l isa front elevation partly in section of a baseless lamp;

Figure 2 is a side elevation of the same lamp showing the relativeposition of the envelope, the glass knob and the metal contacts.

The flashlamp of this invention consists. essentially of the samecomponents with the exception of the brass base as the lamps of theprior art. It has a glass envelope 10, a glass exhaust tube 12,electrical conducting wires 14, a filament 16, an ignition paste 18, afilamentous material 20 serving as the source of actinic light and aglass knob 22.

a light giving lamp. More In the embodiment illustrated in the drawingthe lead in wires 14 through the interior of the flashlamp to thefilament 16 is supported in the outer rim 13 of the exhaust tube whichis slightly beaded at the end 15 to form a ring. The wires 14 extendfrom the inside of the envelop out through the bottom of the lampthrough a kuobular section of glass which is formed during the normalsealing operation by flattening out a section of the glass envelope andexhaust tubulation just below the spherical portion of the envelope. Thewire leads 14 of the illustrated embodiment are then bent back on eitherside of the flattened glass member in such manner as to cause the Wireto lie snugly adjacent to the flattened glass but yet protrude therefromto a suflicient extent to permit the making of a good electrical contactbetween the wire and any spring like metal member which contacts bothsides of the flattened glass knobular member. It is, of course, readilapparent that these contact leads might be positioned somewhatdifferently to obtain the same result particularly if the socket were tobe modified accordingly.

The other remaining component parts of the flashlamp are for the mostpart the same as those normally used in the prior art. The two wireconductors 14 lead to the which the current is carried into,

2,699,659 Patented Jan. 18, 1955 filament 16 which is electricallyconnected to each of the wires 14 at their inner end and with a blob ofan ignition paste 18 usually a zirconium type igniter positionedsufiiciently close to the filament so that any current passing throughthe filament and heating it would serve to ignite the paste and therebyignite the material which is to serve as the source of actinic light. Inthe drawings shown the source is a filamentous material 20 which may beeither drawn or cut metal strips of metal such as aluminum in athickness which is readily ignitable upon ignition of the paste. Lampswhich depend upon paste like compositions instead of metal strips fortheir source of actinic light are, of course, as easily adapted forconversion to the baseless type lamp of this invention.

The flashlamp of this invention as is shown in the drawings has twodistinctive features, the one being that it has entirely eliminated thebrass base. This is important both from a cost position as well as froma conservation position particularly in these times of stress when thegovernment is calling on all industries to conserve on their use ofcopper and brass. The structure shown in the drawing hasfurthereliminated the glass flared portion of the lamp which in prior art lampswas attached at one end by a reentrant seal to the exhaust tube and atthe other to the glass envelope. This not only eliminates anothercomponent part of the prior art lamp but also saves a step in theprocessing thereof.

While it is true that this lamp as shown will probably be used for sometime in a so-called adapter socket which will also most probably be madeout of brass the adapter socket will be useable for firing a great manylamps and need not be thrown away with each used lamp bulb as wouldnormally be the case with the old type of amps.

While the above description and the drawings submitted herewith disclosea preferred and practical embodiment of the baseless flashlamp of thisinvention it will be understood by those skilled in the art that thespecific details of construction and arrangement of parts as shown anddescribed are by way of illustration and are not to be construed aslimiting the scope of the invention.

What I claim is:

1. A baseless type photoflash lamp consisting of a glass envelope, anactinic light source enclosed in said envelope, a pair of electricallead Wires, a tubular preformed stem mount projecting into said envelopeadapted to support the lead wires, a filamentous conductor connectingthe ends of the lead wires Within the envelope and a knobular projectingglass portion formed at the fused junction of said glass tubular stemand said envelope, the ends of said electrical lead wires projectingfrom said glass envelope through said knobular glass portion and formedto present exposed contact surfaces on either side of said kuobularportion.

2. A baseless type photoflash lamp consisting of a glass envelope, anactinic light source enclosed in said envelope, a pair of electricallead wires, a tubular preformed stem mount projecting into said envelopeadapted to support the lead wires, a filamentous conductor conmeetingthe ends of the lead wires within the envelope and a knobular projectingglass portion formed at the fused junction of said glass tubular stemand said envelope, the ends of said electrical lead wires projectingfrom said glass envelope through said knobular glass portion, said endsbeing folded back so as to lie snugly against the side walls of saidkuobular glass portion.

References Cited in the file of this patent UNITED STATES PATENTS2,272,059 Margitta Feb. 3, 1942 2,337,485 Meridith Dec. 21, 19432,359,483 Kuebler Oct. 3, 1944 2,560,924 Brockman July 17, 1951

